Ion-atom collisions

Bransden B H and McDowell M R C 1992 Charge Exohange and the Theory of Ion-Atom Collisions (Oxford Clarendon)... 

To properly describe electronic rearrangement and its dependence on both nuclear positions and velocities, it is necessary to develop a time-dependent theory of the electronic dynamics in molecular systems. A very useful approximation in this regard is the time-dependent Hartree-Fock approximation (34). Its combination with the eikonal treatment has been called the Eik/TDHF approximation, and has been implemented for ion-atom collisions.(21, 35-37) Approximations can be systematically developed from time-dependent variational principles.(38-41) These can be stated for wavefunctions and lead to differential equations for time-dependent parameters present in trial wavefunctions. 

Bransden, B. H. McDowell, M. R. C. Charge Exchange and the Theory of Ion-Atom Collisions Clarendon Oxford, England, 1992. 

B. Low-Energy Electron Emission in Fast Heavy-Ion-Atom Collisions 1. Longitudinal Electron Velocity Distributions... 

In the past few years there has been a very intense effort to understand the process of single ionization in ion-atom collisions. Experiments in this area have followed largely along three main paths recoil-ion momentum spectroscopy... 

In Section III we discuss the applicability of these models for kinematically complete experiments on target single ionization in ion-atom collisions, which have been performed using the technique of recoil-ion momentum spectroscopy. The examples illustrated will include the pioneering experiments [2,4,5] of... 

More details of the emission of ultralow- and low-energy electrons from fast heavy ion-atom collisions may be seen in the doubly differential cross sections as functions of the longitudinal electron velocity for increasing transverse electron velocity. Examples considered in this chapter include singly ionizing... 

Normally these conditions are satisfied in fast highly charged ion-atom collisions. From Eq. (66) we can derive the equations for the singly differential cross sections with respect to the components of the longitudinal momentum distributions for the electron, recoil-ion, and projectile. The longitudinal electron momentum distribution da/dpe for a particular value of p, may be derived by integrating over the doubly differential cross section with respect to the electron energy Ek ... 

After several decades of systematic electron spectroscopy in ion-atom collisions by many groups (for recent reviews see Refs. 13 and 51), there are only two data sets of doubly differential experimental cross sections cfa/dE dfl for the emission of electrons with < 1 eV. It has been only recently that, with entirely new and extremely efficient electron spectrometers combined with recoil-ion momentum spectroscopy [52], doubly differential cross sections for ultralow -and low-energy electrons (1.5 meV < < 100 eV) have been obtained by... 

This review illustrates the complementary nature of recoil-ion momentum spectroscopy, projectile scattering measurements, and conventional electron emission spectroscopy in ion-atom ionizing collisions. We have examined recent applications of both the CDW and CDW-EIS approximations from this perspective. We have shown that both models provide a flexible and quite accurate theory of ionization in ion-atom collisions at intermediate and high energies and also allows simple physical analysis of the ionization process from the perspective of these different experimental techniques. 

N. Stolterfoht, R. D. DuBois, and R. D. Rivarola, Electron Emission in Heavy-Ion Atom Collisions, Vol 20, J. P. Toennies, ed., Springer-Verlag, Berlin, 1997. 

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